Piano striking mechanism

ABSTRACT

Disclosed is a striking mechanism for use in pianos and related instruments having a plurality of strings to produce musical notes and a plurality of keys to select the musical notes. A plurality of lever arms are pivotally mounted within a frame which encloses the striking mechanism. Each lever arm engages a hammer within the frame, communicates with one of the keys, and is adapted for driving a hammer against one or more strings to produce a musical note.

Waited States Patent 1 Qarbone [111 3,757,026 [451 Sept. 4, 1973 PIANO STRIKING MECHANISM [76] Inventor: Jorge L. Carbone, 2104 12th St.,

Cuyahoga Falls, Ohio 44223 [22] Filed: July 27, 1972 [21] Appl. No.: 275,563

[52] US. Cl 84/236, 84/202, 84/250 [51] Int. Cl Gl0c 3/18 [58] Field of Search 84/12, 27-29,

[56] References Cited UNITED STATES PATENTS 420,914 2/1890 Muller 84/202 1,615,228 l/l927 Marthy 84/202 2,271,460 1/1942 Miessner 84/236 8/1960 Sluyter 84/236 3/1972 Erbert et al 84/236 Primary Examiner-Richard B. Wilkinson Assistant Examiner-Lawrence R. Franklin Attorney-Hamilton, Renner & Kenner [57] ABSTRACT Disclosed is a striking mechanism for use in pianos and related instruments having a plurality of strings to produce musical notes and a plurality of keys to'select the musical notes. A plurality of lever arms are pivotally mounted within a frame which encloses the striking mechanism. Each lever arm engages a hammer within the frame, communicates with one of the keys, and is adapted for driving a hammer against one or more strings to produce a musical note.

16 Claims, 7 Drawing Figures PAIENIEB m SHEEI 3 OF 3 l PIANO STRIKING MECHANISM BACKGROUND OF THE INVENTION The present invention relates generally to a piano or similar musical instrument having a frame wherein a plurality of lever arms move a similar number of hammers to strike the strings in response to actuation of the mechanism by depression of the instrument's keys.

The mechanical complexity of the modern piano appears to have developed to its furthest limits. Historically, the piano descended from instruments such as the clavichord whose strings were struck and the harpsichord whose strings were plucked, and gradually replaced both as it gained popularity. The paino was designed to afford the player control over the duration of his notes. A hammer was needed which would strike the string and immediately fall away even while the key remained depressed. Upon release of the key, simultaneous application of a damper to the vibrating string must be had in order to terminate the particular note.

Several early developments led to the double escapement mechanism which has remained substantially unchanged to the present time. The escapement mechanism has a lever which throws the hammer against the string then immediately slips away or escapes from the hammer and is thereafter free from control by the key. A second escaper catches the hammer as it falls away from the string and causes it to hesitate during its return so that the first escaper has time to re-establish its striking position. The result is that the key may act upon the hammer even before the hammer has returned to its reposing position providing the capability for the rapid repetition of a note.

In order to utilize the double escapement mechanism a large number of moving parts are required to function in perfect harmony. At least one known piano manufacturer uses over fifty parts for each action, or a total of more than 4,500 parts for the 88-note keyboard. The components must be capable of withstanding constant friction without lubrication and without wear and the manufacturers require a degree of precision approaching watchmaking.

Although the double escapement mechanism performs extremely satisfactorily and the careful selection of materials therefor insures a long life, its .one disadvantage is the number of parts required. This reflects a huge expenditure of time for construction and assembly as well as for repairs when failures do occur. Since it would be difficult to delete any parts from the double escapement mechanism, it is understandable that few, ifany, developments have been made to that end. However, there has also been a lack of development of other striking mechanisms and it is not unreasonable to assume that a simpler form of striking mechanism one having fewer components per note would be desirable since it could more readily be produced and at a reduced cost.

SUMMARY OF THE INVENTION An object of the invention is to provide a striking mechanism for pianos which possess the qualities and capabilities of the double escapement mechanism but which has considerably less component parts resulting in a reduction in costs of construction of the parts and assembly of the piano, as well as the labor expended in relation thereto.

Still another object of the invention is to provide a mechanism which requires less space than conventional mechanisms and one which is easily maintained. A still further object of the invention is to provide a mechanism having only a few basic components which are readily interchangeable and which are not adversely affected by atmospheric conditions.

Yet another object of the present invention, in harmony with the basic concept of simplicity of construction, is to provide interchangeable components for readily mounting the keys in pivotal relation to the striking mechanism. A still further object of the invention is to provide a means of mounting the piano wires in order to reduce the frequency of piano tunings as well as the time and cost expended therefor.

In general, the invention relates to a striking mechanism for use in pianos and related instruments having a plurality of strings to produce musical notes and a plurality of keys to select the notes. An exemplary striking mechanism comprises a frame for pivotally mounting a plurality of lever arms engaging a like plurality of hammers, each lever arm communicating with one of the keys and being adapted to drive one of the hammers against the string or strings to produce a musical note. I

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation partially in section of a strking mechanism for use in an upright piano;

FIG. 2 is a side elevation, partially in section, depicting a frame or channel member for pivotally mounting the instrument keys;

FIG. 3 is a broken away perspective view of the channel member depicted in FIG. 2;

FIG. 4 is a perspective view of a removable key guide as seen in FIG. 2;

FIG. 5 is a broken away perspective view of a frame or support member for a piano mechanism;

FIG. 6 is a side elevation partially in section of a striking mechanism for use in a grand piano; and,

FIG. 7 is an exploded perspective view of a locking tuning pin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to the drawings, a striking mechanism according to the present invention is indicated generally by the numeral 10. The mechanism 10 is designed for movement of its hammers in a generally horizontal plane against one or more strings, generally vertically disposed. As such, the mechanism 10 is particularly suitable for use in an upright piano.

The mechanism 10 is activated by a key 11 which moves a lever or drive link, indicated generally by the numeral 12, mounted bya plate or mounting element indicated generally by the numeral 13, carried within a frame, generally 14. A hammer, indicated generally by the numeral 15, engages drive link 12 and is movable against at least one string S, in response to depression of key 11 to produce a musical note. A damper 16, is provided to control the vibration of the string and thereby sustain and terminate the note as desired.

The manner in which each key is mounted is best shown in FIGS. 2 and 3. Each of the keys 1.1 is mounted on an individual key pivot plate indicated generally by the numeral 20. Each pivot plate 20 is carried by a frame of channel member 21. For ease of construction and assembly it is preferable to manufacture the keys 11 from plastic, the pivot plates 20 of nylon and channel member 21 of extruded aluminum.

The channel member 21 has a bottom surface 22, an end wall 23 facing the striking mechanism 10, and an upper surface 24 interrupted by a slot 25 traversing the width of channel member 21 which is of sufficient width to mount all of the keys 11. The bsttom surface 22 is inclined upwardly away from the striking mechanism to meet upper surface 24 forming a hollow chamber 26. A solid leg 28 projects from the juncture of bottom surface 22 and upper surface 24 and is provided with a transversely extending T-shaped slot 29.

The pivot plates 20 each have a rectangular base 30 which rests upon the upper surface 24 of channel member 21. A leg 31 extends from the underside of base 30 interfitting with slot 25 and a second rectangular surface 32, carried by the leg 31, maintains pivot plate 20 within the slot 25. Perpendicular to and along the length of the upper surface of each base 30 is a plate 33 having the shape of a right trapezoid. The uppermost surface of plate 33 has a key-shaped slot 34 terminating in a circular bore 35. An inclined surface 36 extends from the upper surface 33 to the base 30.

It is customary for pianos to have a plurality of long white keys alternated with a plurality of shorter black keys. Mounting of a white key is depicted in FIG. 2, it being understood that the black keys are treated in the same manner. Each key 11 has a longitudinally extending slot 40 in its underside to freely receive one of the trapezoid plates 33. A pivot pin 41 is held within the side walls of key 11 passing through the slot 40. When the pin 41 is snapped into the bore 35 in plate 33, the key 11 is able to rock or pivot about that point when depressed.

To mount a white key, the pivot plate 20 is slid into the slot 25 in channel member 21 from one end with its inclined surface 36 facing toward striking mechanism 10. To mount a black key, the pivot plate 20 is merely turned around, so that its inclined surface 36 faces toward the depressed end of the key, and it is then slid into slot 25 in channel member 21. In this manner each of the white keys has a pivot point A further from the striking mechanism 10 than the pivot point B for the black keys. The two pivot points A and B are required for the same amount of elevation at the striking end of both the white and black keys in response to depression thereof. As seen in FIG. 3, the rectangular bases 30 of pivot plates 20 contact one another to assure proper spacing of the keys 11. When all of the plates 20 are within slot 25, bolts 42 passing througn a bore 43 in end wall 23 and threadably engaging a bore 44 in the inclined portion of bottom surface 22, are tightened to maintain the plates 20 within channel member 21.

A plurality of guide pins 45 are provided with arched bases 46 of flexible steel or other suitable material and are slid into the T-shaped slot 29 in leg 28. The bases 46 contact each other within slot 29 forming a row of guide pins, one for each key. Retainers (not shown) may be fastened at opposed ends of the slot 29 to eliminate any movement of guide pins 45. The guide pins 45 maintain the alignment of the longer, white keys with each white key having a bore 48 overfitting a guide pin 45. One or more layers of felt 49 or similar cushioning material are positioned over pin 45 to minimize the sound of key 11 being depressed. A similar layer of felt material 50 or the like, may be positioned under leg 28 wherever the latter contacts a frame support member 51 which is fastened to the piano body via screws 52.

Referring now to FIG. 1, the striking mechanism 10 for an upright piano will be described in detail. The activating end, 11A of each of the keys 11 is provided with a stud 60 for activating the striking mechanism 10 in response to the application of force at the other end of the key. The stud 60 has a lower threaded portion 61 which engages a threaded bore 62 in key 1 1. The upper portion of stud 60 is capped with felt or similar cushioning material 63.

The stud 60 engages drive link 12 which is manufactured from a suitable plastic material. Link 12 includes a base 64 having an annular bearing 65 encompassing both sides of a bore 67 passing through the lower portion of the base 64. The forward edge of base 64, i.e., that which faces the strings S, is formed by the juncture of an upper cam surface 66 with a lower cam surface 68. The shape of cam surface 66 is defined by an arc of a circle centered about the bore 67 while cam surface 68 is from a circle of greater radius the purpose for which will be hereinafter described. A tang 69 projects rearwardly from the base 64 and a vertically disposed arm 70 extends upwardly from the base. At the end of arm 70 is an arcuate drive sector 71, consisting of a plurality of teeth 72. The drive sector 71 has a shape defined by an arc of another circle centered about the bore 67.

Each drive link 12 is carried by a mounting element 13 which may be manufactured from nylon. All of the elements 13 are mounted within the tubular frame 14 (FIG. 1) which may be a section of plastic pipe having a width greater than that of the keyboard. Both ends of frame 14 are circularand are fastened to the interior of the piano by suitable means (not shown). Several inches from both ends a chord-shaped segment is removed from the upper surface of frame 14, forming a longitudinal slot having an upper forward edge 73 and an upper rearward edge 74. A similar chord-shaped segment is removed from the lower surface, several inches from both ends of channel 14 forming a second longitudinal slot having a lower forward edge 75 and a lower rearward edge 76. The upper slot, between ends 73 and 74. affords clearance for the movement of drive links 12 and hammer 15 while the lower slot, between ends 75 and 76 accommodates the mounting elements 13.

Each mounting element 13 has a forward notch 78, engaging lower forward edge 75 of frame 14 and a rearward notch 79, engaging lower rearward edge 76. Toward the rear half of element 13 is a key-shaped slot which permits deformation of element 13. Thus, by urging notches 78 and 79 together, the element 13 may be readily positioned between the edges 75 and 76 in frame 14 and will remain thereagainst upon release of the notches 78 and 79 due to the resilience of element 13. Each element 13 carries an opposed pair of ears 8] along both sides of the upper surface of notch 78, frictionally engaging the forward edge 75 of frame 14, and a second pair of opposed ears 82 along both sides of the upper surface of notch 79, engaging the rearward edge 76 of frame 14. The ears 81 and 82 maintain adjacent elements 13 at proper intervals within frame 14. Each element 13 is further provided with a pivot stud 83 for mounting a drive link 12 within the bore 67 and annular bearing 65 thereof. A second pivot stud 84 is also carried by element 13 for pivotally mounting a damper actuator 85.

The damper actuator 85 has a cam follower arm 86 provided with a stud 88 carrying a cam follower 89,

preferably of nylon. At the opposite end of actuator 85, a key-shaped slot 90 carries a stud 91 projecting from an end 92 of damper connecting rod 93. The opposite end of rod 93 passes through the head 94 of damper 16 which may be formed from wood and is attached thereto by means of nuts 95. Several layers of felt or woolen material form the foot 96 of the damper 16 wich id adjusted by means of nuts 95 to repose against the string S until the key 11 is depressed.

While the damper 16 permits the string S to resonate so long as the key 11 is depressed, it is often necessary to sustain the note after releading the key 11. To accomplish this the connecting rod 93 has an offset 98 which may be formed by two right angled bends therein. A bracket 99, preferably of aluminum, extending beyond the width of the keyboard, is pivotally mounted to the piano by passing screws 100 through annular shoulders (not shown) provided at the ends thereof. The conventional foot pedal linkage of the piano may be fastened to the upper end 101 of bracket 99 by any suitable means so that depression of the foot pedal will raise end 101 causing lower end 102 of bracket 99 to move rearwardly against neck 98, simultaneously withdrawing all of the dampers 16 away from the strings S. Cushioning material 103 may be applied to end 102 to eliminate any sound when neck 98 is struck. One or more brackets 104 may be provided having bores therethrough lined with felt, as at 105, for the passage and supports of connecting rods 93. Of course, each damper 16 may be moved in response to depression of a key 11 as will be described hereinafter.

Simultaneous with rearward movement of a damper 16, the hammer is driven forward to strike one or more of the strings S as each key 11 is depressed. The hammer 15 is a rectangularly shaped member which may also be manufacture from a suitable plastic. The lower edge 120 of the rearward half 121 of hammer 15 is provided with a row of teeth 122 which interfit and coact with the teeth 72 of drive link 12. The forwrd half 123 of hammer 15 has a bottom edge 124 lower than edge 120 an seperated therefrom by a rear flange 125. The bottom edge 124 is terminated by a front flange 126 which also extends above the upper edge 128 of hammer 15.

At the forward end of thehammer 15 is a head 129 which is preferably formed from wood and is fastened by suitable means (not shown) to front flange 126. As is customary, the strings in the piano are generally diagonally disposed in order to mount all of them on the iron frame. Therefore, each head 129 may be rotated several degrees and then fastened to flange 126 in order to dirctly strike the strings S. High grade woolen felt, 130 is secured to each head 129 in a customary manner, for striking the string S.

Each hammer 15 is supported by a trough-shaped plastic support member 131 having front and rear flagnes 132 and 133, respectively, and a flat base 134. A glass liner 135 rests upon base 134 and a hollow plastic roller element 136, having annular flanges 138 at both ends, rohls teereon between flanges 132 and 133. The bottom edge 124 of hammer 15 rests upon roller 136 as it moves toward and away from the strings S, while the flanges 138, extending slightly above the bottom edge 124 maintain alingnment of the roller 136 under the hammer 15. Below the base 134 and extending therefrom is a leg 139 to which is fastened via screws 140, a layer of fairly rigid cushioning material 141 to silence the return movement of bracket 99.

Another spport member 142, having the shape of an inverted trough, is preferably formed from aluminum, extends above all of the hammers 15 and is mounted within the piano by suitable means (not shown). The support 142 has a flat upper surface 143 with downwardly extending front and rear walls, 144 and 145, re-

spectively. The front wall 144 is further provided at its base with a forwardly extending flange 146 wich is pro- .vided with a series of threaded bores 148 therethrough,

there being one above each hammer 15. An alignment screw 149 engages each bore 148 and extends into a laterally extending slot 150 which extends across the upper edge 128 of hammer 15 prohibiting lateral movement thereof during movement toward and away from the string S. A dust cover 151 of aluminum or other suitable material is positioned over the striking mechanism 10 by passing screws 152 therethrough into support 142.

Having thus described the component parts of the mechanism 10, its operation may now be explained. When a key 11 is depressed, the inner end thereof, carrying the stud 60, will rise against tang 69. As tang 69 is driven upwardly, the drive link 12 rotates about pivot stud 83 and teeth 72 drive teeth 122 and the hammer 15 forward in a linear direction. At the same time, cam follower 89 is urged downwardly by cam surface 68 causing the damper actuator to rotate about pivot stud 84. This rotation moves the lower end of actuator 85 carrying connecting rod 93 and the dampler 16 away from the string S. Once the damper 16 is away fromthe string S the second cam surface 66 maintains that position so that the remainder of the force applied to the key 11 may be utilized to drive the hammer l5 forward.

As the drive link 12 continues to rotate, the teeth 72 coact with the teeth 122 to drive the hammer 15 from its resting position, indicated generally by A, to the chain line position 130B. The momentum of the hammer 15 carries it forward striking the string S, as at 130C. After contact with the string S, the hammer 15 quickly rebounds to position 1308. To aid the com- -plete and instant return of drive link 12, hammer l5 and damper 16 to their pre-struck position upon the release of key 11, a wire spring 153 may be utilized. The upper end 154 of spring 153 is held within a notch 155 in upper arm 70 of link 12. As it extends downwardly, spring 153 is maintained on link 12 by passing in front of a first stud 156 thereon and then behind a second stud 158. Below stud 158 the spring 153 curves around pivot stud 65. The lower end 159 of spring 153 is positioned within a bore 160 passing through damper actuator 85. Depression of a key 11 initially withdraws the damper 16 from the string S biasing the lower half of spring 153. As the link 12 moves forward the upper end of spring 153 is biased against a stud 161 provided on mounting element 13. Upon release of the key 11 the spring 153 quickly returns to its normal position, withdrawing link 12 and hammer 15 from the string S while returning the damper l6 thereto.

Referring now to FIGS. 5 and 6, a striking mecha-' nism, referred to generally by the numeral 200, functions similarly to striking mechanism 10, but has been specially adapted for use in a grand piano, i.e., for the vertical movements of the hammers against horizontally displaced strings.

The mechanism 200 is activated by a key 201 which may be pivotally mounted within the channel member 21 as hereinbefore described. The key 201 moves a lever or drive link, indicated generally by the numeral 202, mounted by a plate or mounting element, indicated generally by the numeral 203, carried by a frame generally 204. A hammer, indicated generally by the numeral 205, engages drive link and is movable against at least one string S in response to depression of key 201 to produce a musical note. A damper 206, is provided to control the vibration of the string and thereby sustain and terminate the note as desired.

The frame 204, which may be manufactured from aluminum, traverses the width of the keyboard and is carried in a suitable manner by a plate 208 fastened to the interior of the piano via screws 209. The base of frame 204 has a forwardly displaced foot 210 and a rearwardly displaced foot 211. Between feet 210 and 21 1 is a recess 212 which permits movement of the activating end, 201A of key 201. Felt or similar cushioning material 213 is provided at the activating end 201A for contact with recess 212. Similar material 214 is provided at the underside of foot 211 for contact by key 201.

As best shown in FIG. 5, the frame 204 has a C- shaped track 215 extending the width of the frame 204 over foot 210 and having upper and lower vertically displaced flanges 216 and 218 (FIG. 6), respectively. A T-shaped slot 219 also extending the width of channel 204, over foot 211, has front and rear horizontally displaced flanges, 220 and 221, respectively. A central body portion 222 extends above both track 215 and slot 219 terminating in an upper ledge 223. The forward edge of ledge 223 is extended to form a recess 224 with a lower ledge surface 225.

A bore 226 extends through the upper ledge 223, down through the body 222 and through the recess 212 of frame 204. An actuating stud 228 passes therethrough resting on key 201 and engaging drive link 202. Felt or similar cushioning material 229 is affixed to the end of stud 228 to silence contact between the drive link 202 and stud 228. A bolt 239 passes through the foot 210, through the track 215 and threadably engages the upper portion 231 thereof which functions to draw flanges 216 and 218 together.

A plurality of mounting elements 203, which may be manufactured from nylon, have vertically disposed feet 235 which are slid into the track 215 in channel 204. Each element 203 also has a horizontally displaced foot 236 which rests upon surface 225 and extends into recess 224. The feet 235 and 236 serve to maintain proper spacing between adjacent elements 203.

The uppermost portion 238 of element 203 has a stud 239 and spacer 240 formed integrally thereon. lmmediately below spacer 240 is an arcuate flange 241 and at the corner opposite the stud 239 there is an ovalshaped stud 242. Both the flange 241 and stud 242 are utilized in conjunction with a return mechanism for the drive links 202 which will be described hereinbelow. An additional stud, 243, is provided for pivotal mounting of a drive link 202.

The drive links 202, one of w hich is shown in FIG. 6, are manufactured from a suitable plastic material. Each link 202 has a central portion 245 with a bore 246 therethrough to receive the stud 243 from element 203. The upper side of central portion 245 is formed by the juncture of a forward cam surface 248 and a rearward cam surface 249. The shape of cam surface 249 is defined by an arc of a circle centered about pivot stud 243 while cam surface 248 is from a circle of greater radius, the purpose for which will be described hereinafter.

An arm 250 extends away from central portion 245 and is provided at the end thereof with an arcuate drive sector 251 consisting of a plurality of teeth 252. The sector 251 is defined by an arc of another circle centered about pivot stud 243. A triangularly-shaped rocker 253 extends from both sides of arm 250 downwardly so that its apex rests upon activating stud 228 and cushion 229. A second arm 254 extends away from the central portion 245 and serves to balance drive link 202.

Each element 203 also carries a damper actuator 255 having a bore 256 for receipt of pivot stud 239. The actuator 255 has a cam follower arm 258 provided with a stud 259 carrying a nylon cam follower 260. The opposite end of actuator 255 is clevis-shaped to hold the end 261 of damper connecting rod 262 as by a pin 263. Each connecting rod 262 passes through an aluminum support 264, the bores of which are lined with felt or similar cushioning material 265. The rod 262 has an offset 266 formed by two right angled bends and is connected to damper 206 by nuts 268. Felt or woolen pads form the foot 269 of damper 206.

As in the embodiment of striking mechanism 10, a bracket 270, pivotally carried by a support 271, is connected to foot pedal linkage (not shown) by arm 272, for the simultaneous withdrawal of all dampers 206 from the strings S when desired. Felt or similar cushioning material 273 and 274 is provided at both ends thereof to minimize the sounds of contact between the bracket 270, the rod 262, and the support 264. A plate 275 carries the support 264 and is mounted within the piano by screws 276.

As the dampers 206 are individually withdrawn from the strings S by damper actuators 255, the hammers 205 are driven upwardly toward the strings S in response to depression of a key 201. Each hammer 205 may be manufactured from plastic and has a short base 280 which includes a row of vertically extending teeth 281 extending therefrom engaging and coacting with teeth 252 from drive link 202. The teeth 281 terminate at the central section 282 of hammer 205 which continues upwardly to form the upper base 283.

At the forward end of the hammer 205 is a head 284 which is preferably formed from wood and is fastened by suitable means (not shown) to base 283. As is customary, the strings in the piano are generally diagonally disposed in order to mount'all of them on the iron frame. Therefore, each head 284 may be rotated several degrees and then fastened to base 283 in order to directly strike the strings. S. High grade woolen felt 285 is secured to each head 284 in a customary manner, for striking the string S.

Each hammer 205 is supported and maintained in position by a cylindrical steel guide rod 290, the lower end of which is threaded to engage a flange 291 and base element 292. As indicated in FIG. 6, each guide rod 290 is slid into slot 219 in channel member204 with flange 291 and base element 292 gripping the flanges 220 and 221 thereon. The rods 290, which are adjustable upwardly and downwardly, are spaced at proper intervals by base elements 292 which are themselves maintained within slot 218 by retainers at both ends of the piano (not shown). The base 280 and central section 282 have a longitudinally extending bore 293 therethrough which receives guide rod 290. Cushioning material 294 silences the return of hammer 205 after it has struck a string S.

Having thus described the component parts of the mechanism 200, its operation may now be explained.

When a key 201 is depressed, its activating end 201A is raised in the same manner as was described hereinabove with respect to key 11. The end 201A raises the actuating stud .228 which contacts and drives rocker 253 upwardly causing the drive link 202 to rotate in a counterclockwise manner, as viewed in FIG. 6, so that teeth 252 thereon coact with the teeth 281 to drive the hammer 205 in a linear direction, in this case, upwardly. At the same time, cam follower 260 is urged upwardly by cam surface 248 causing the damper actuator 255 to rotate about pivot stud 239. This rotation moves the clevis-shaped end of actuator 255 downwardly, pulling cwnnector rod 262 and the damper 205 away from the string S. Once the damper 206 is away from the string S, the second cam surface 249 maintains that position so that the remainder of the force applied to the key 201 may be utilized to drive the hammer 205 upward.

As the drive link 202 continues to rotate, the teeth 252 drive the hammer 205 from its resting position, indicated generally by 285A, to the position 285B, indicated by chain lines. Momentem of the hammer 205 continues to carry it upwardly to strike the string S as at position 285C and then to fall quickly away to position 285B where cushion 294 rests upon rod 290.

While the hammer 205 will return to its resting position 285A due to grivity, upon release of key 201, a wire spring 295 may be utilized to assure the complete and instant return hammer 205, drive link 202 and damper 206 to their pre-struck positions. The forward end of spring 295 is maintained within a notch 296 in damper-actuator 255. The spring 295 curves around and between the spacer 240 (FIG. 6) and arcuate flange 241 of mounting element 203 and continues onward, under cam follower 260, terminating in a notch 298 in drive link 202. When the link 202 is fully extended, as indicated by chain lines in FIG. 6, the oval stud 242 biases the spring 295 between arcuate flange 241 and notch 298 creating a clockwise force upon link 202 urging its return to the pre-struck position.

Both striking mechanisms 10 and 200 provide for the smooth and rapid as well as silent movement of the hammers, l5 and 205, respectively, against the strings S and back to their pre-struck position. Either mechanism will permit the pianist to rest his fingers upon the keys 11 or 201 lightly without producing a note since mechanically the hammers 15 and 205 are only extended to positions 1298 and 2858, respectively. When a note is intended, however, a conventional amount of force, usually between 55 and 70 grams, applied to the keys 11 and 201, will drive the hammers 15 and 205 to strike the strings S, positions 129C and 285C, respectively, and then fall quickly back to positions 129B and 2853, so long as the keys 11 and 201 remain depressed, assuring full vibration of the strings S. The mechanisms 10 and 200 are fully capable of affecting the rapid repetition of any particular note dependent upon the agility of the pianist as is true with pianos of the prior art. Likewise, the mechanisms 10 and 200 are capable of reproducing the full expressions of the pianist, for an increasing amounts of force are applied to the keys 11 and 201, the more pronounced will be the notes.

Although both striking mechanisms 10 and 200 may beincorporated within conventional pianos, it is possible to provide such an instrument with locking tuning pins eliminating the necessity for frequent re-tuning operations which is in keeping with the time and maintenanace serving objectives characterized by the improved striking mechanisms described hereinabove.

It is standard to provide one string S per note in the lower range, two strings S per note for the mid-range, and three strings S per note for the upper range. Each string is held immovable by a wrest pin at the lower end of the frame and adjustably at the upper end thpreof by an individual threaded tuning pin. The strings S normally bear a tension of 200 pounds each when in tune which force acts to gradually unscrew the pin with the resultant loss of pitch.

Referring to FIG. 7,a tuning pin 310, has a square head 31 1 for turning with a wrench, and an upper cylindr'ical body 312 about weich the string S is wrapped after passing through a bore 313 into body 312. An annular flange 314 maintains the string S on body 312. A lower cylindrical body portion 315 extends beyond flange 314 and has a threaded end 316.

A plastic tubular member, generally 318, has a conical head 319 and a cylindrical base 320. A small vertically displaced lug 321 is carried on the side wall of head 319 and a longitudinally extending slot 322 passes terough the center of head 320. A bore 323 passes through the center of member 318 to receive the lower body 315 of pin 310. A spacer 324 fits over the body 315 of pin 310 and a nut 325 threadably engages end 316 of pin 310.

Referring to FIG. 1, a modified frame 330, is provided for mounting the pins 310. While conventional frames mount both wrest pins and tuning pins on the same face, the frame 330 has a top edge 331 at right angles to the front face 332 for the mounting of the tuning pins 310, the wrist pins (not shown) being mounted on the lower portion of front face 332. The edge 331 is provided with a plurality of flared bores 333 to receive the inserts 318 and a groove 334 engages lug 321. The wooden sounding board 335 is fastened to the rear of frame 330 via screws 336.

As each string S is led from its wrest pin, it passes over a right angled support 338, of hard plastic or other suitable material, and to the pin 310, passing through the bore 313 therein and around the upper body 312. The pin 310, and the insert 318 in which it is carried, are both inserted into bore 333 with groove 334 engaging lug 321. The washer 324 is placed over the lower body 315 and the nut 325 is threaded onto end 316.

The string S is then tuned to the proper pitch by tuning head 311 while holding nut 325. When the string S has been tuned, the pin 310 may be locked by holding head 311 and tightening nut 325. As this is done the flange 314 on pin 310 will bear down on the member 318 compressing it about the body 315 of pin 310 by virtue of the slot 322. When the nut 325 is tight it will be holding the pin 310 against the underside of edge 331, the insert 318 will frictionally engage and restrict rotation of pin 310 and the groove 334 will prohibit rotation of the insert 318.

A steel plate 339 is positioned over all of the strings S and the support 338 and is fastened to the frame 330 by bolts 340. A inged dust cover 341 may be affixed to the top edge 331 and extends over the tuning pins 310. It is to be understood that although the locking mechanism has been described in conjunction with a piano, it may als be used with a harp or other stringed instrument.

From the foregoing description, it should be apparent to one skilled in the art that the improved striking mechanisms and locking tuning pins disclosed herein will facilitate a reduction in the time and expense in producing pianos as well as maintaining them, and yet such piano embodying these improvements is nonetheless playable, without the sacrifice of tonal quality.

I claim:

1. A striking mechanism for use in pianos and related instruments having at least one string to produce a musical note and at least one key to select the musical note, the striking mechanism comprising; frame means, hammer means for striking a string, drive means for actuation by the key, coacting gear means for imparting motion to said hammer means from said drive means, and guide means for constraining the motion of said hammer means to a linear motion to strike the string.

2. A striking mechanism, as in claim 1, further comprising; means for mounting said drive means on said frame means and means for controlling the vibration of the string.

3. A striking mechanism, as in claim 2, wherein said means for mounting includes an element adapted to be slid into said frame means and carrying a pivot stud holding said drive means, andsaid means for controlling the vibration of the string includes a damper, a damper actuation and a connecting rod therebetween.

4. A striking mechanism, as in claim 3, wherein said element carries a second pivot stud mouting said damper actuator.

5. A striking mechanism, as in claim 3, wherein said drive means comprises; a drive link having a bore for receiving said pivot stud and at least one cam surface engaging said damper actuator.

6. A striking mechanism, as in claim 1, wherein said coacting gear means comprises; an arcuate segment on said drive means having at least one tooth thereon for engaging said hammer means.

7. A sriking mechanism, as in claim 1, including means for mounting said hammer means carried by said frame means.

8. A striking mechanism, asin claim 7, wherein said means for mounting said hammer means consisting of a cylindrical guide rod.

9. A striking mechanism, as in claim 1, wherein said hammer means includes a movable head for striking the string and said coacting gear means further comprises; at least one tooth on the rear portion of said hammer means to engage said drive means.

10. A striking mechanism, as in claim 9, wherein said guide means for said hammer means is a roller.

11. A striking mechanism, as in claim 9, wherein said guide means for said hammer means is a rod.

12. A striking mechanism, as in claim 1, wherein a spring means urges said drive means and said hammer means away from the string.

13. A striking mechanism, as in claim 1 further comprising; a second frame means, a plurality of removable plates carried by said second frame means, each said removable plate pivotally mounting a key, and at least one removable guide pin for alignment of at least one key upon said frame.

14. In pianos and related instruments having at least one string to produce a musical note wherein said string is tensioned between a wrest pin and a tuning pin, both carried by a frame, a means for locking said tuning pin to maintain the desired tension of the string, wherein said tuning pin comprises a body portion passes through said means for locking, a head at one end of said body portion, the other end of said body portion being threaded to receive a nut, and a flange on said body portion between said head and said other end so that upon rotation of said head with respect to the nut said flange bears against said means for locking to prohibit rotation of said tuning pin and wherein said means for locking comprises a tubular member having a cylindrical base and a conically-shaped head and slot means in said conically-shaped head for constricting said conically-shaped head around said body portion of said pin.

15. In pianos and related instruments, as in claim 14, wherein said conically-shaped head carries projecting means for restricting rotation of said conically-shaped head and said pin when both are positioned within the frame.

16. In pianos and related instruments, as in claim 15, wherein said slot means is a longitudinal slot in said conically-shaped head, and s aid projecting means is a lug on the outer surface of said conically-shaped head. l i 

1. A striking mechanism for use in pianos and related instruments having at least one string to produce a musical note and at least one key to select the musical note, the striking mechanism comprising; frame means, hammer means for striking a string, drive means for actuation by the key, coacting gear means for imparting motion to said hammer means from said drive means, and guide means for constraining the motion of said hammer means to a linear motion to strike the string.
 2. A striking mechanism, as in claim 1, further comprising; means for mounting said drive means on said frame means and means for controlling the vibration of the string.
 3. A striking mechanism, as in claim 2, wherein said means for mounting includes an element adapted to be slid into said frame means and carrying a pivot stud holding said drive means, and said means for controlling the vibration of the string includes a damper, a damper actuation and a connecting rod therebetween.
 4. A striking mechanism, as in claim 3, wherein said element carries a second pivot stud mouting said damper actuator.
 5. A striking mechanism, as in claim 3, wherein said drive means comprises; a drive link having a bore for receiving said pivot stud and at least one cam surface engaging said damper actuator.
 6. A striking mechanism, as in claim 1, wherein said coacting gear means comprises; an arcuate segment on said drive means having at least one tooth thereon for engaging said hammer means.
 7. A sriking mechanism, as in claim 1, including means for mounting said hammer means carried by said frame means.
 8. A striking mechanism, as in claim 7, wherein said means for mounting said hammer means consisting of a cylindrical guide rod.
 9. A striking mechanism, as in claim 1, wherein said hammer means includes a movable head for striking the string and said coacting gear means further comprises; at least one tooth on the rear portion of said hammer means to engage said drive means.
 10. A striking mechanism, as in claim 9, wherein said guide means for said hammer means is a roller.
 11. A striking mechanism, as in claim 9, wherein said guide means for said hammer means is a rod.
 12. A striking mechanism, as in claim 1, wherein a spring means urges said drive means and said hammer means away from the string.
 13. A striking mechanism, as in claim 1 further comprising; a second frame means, a plurality of removable plates carried by said second frame means, each said removable plate pivotally mounting a key, and at least one removable guide pin for alignment of at least one key upon said frame.
 14. In pianos and related instruments having at least one string to produce a musical note wherein said string is tensioned between a wrest pin and a tuning pin, both carried by a frame, a means for locking said tuning pin to maintain the desired tension of the string, wherein said tuning pin comprises a body portion passes through said means for locking, a head at one end of said body portion, the other end of said body portion being threaded to receive a nut, and a flange on said body portion between said head and said other end so that upon rotation of said head with respect to the nut said flange bears against said means for locking to prohibit rotation of said tuning pin and wherein said means for locking comprises a tubular member having a cylindrical base and a conically-shaped head and slot means in said conically-shaped head for constricting said conically-shaped head around said body portion of said pin.
 15. In pianos and related instruments, as in claim 14, wherein said conically-shaped head carries projecting means for restricting rotation of said conically-shaped head and said pin when both are positioned within the frame.
 16. In pianos and related instruments, as in claim 15, Wherein said slot means is a longitudinal slot in said conically-shaped head, and s aid projecting means is a lug on the outer surface of said conically-shaped head. 